In a semiconductor test apparatus, inspection of semiconductor devices is conducted by bringing a probing needle of a probe card or a contact probe such as a membrane probe into contact with electrode pads of multiple semiconductor devices formed on a wafer, applying a test signal from a test head, and detecting output signals from the semiconductor devices.
The inspection of semiconductor devices is conducted by adjusting the atmosphere temperature to a temperature matching the conditions at which the semiconductor devices are used. Therefore, the inspection is conducted not only in a high-temperature atmosphere, but also in a low-temperature atmosphere. When the inspection is conducted by setting an atmosphere temperature to a low temperature, condensation sometimes occurs on the periphery of wafer or probe card. When condensation occurs on the wafer or probe card, it causes degradation of electric characteristics such as short circuit of exposed wiring patterns or leak increase and also contaminates the surface. For this reason, an apparatus for introducing a dry gas to the probe card surface (for example, Japanese Patent Applications Laid-open No. 11-026523) or an apparatus for introducing a dry gas around a wafer (for example, Japanese Patent Applications Laid-open No. 2003-179109) have been used in the semiconductor test apparatuses to prevent the occurrence of condensation.
The progress recently achieved in the field of semiconductor devices that are the objects of measurement created a demand for improved performance of semiconductor test equipment. In particular, when measurements are conducted to determine the capacity of gate insulating film, evaluate strain characteristics of transistors, and evaluate RF characteristics of transistors, the frequency of signals employed in the measurements extends to a HF band or RF band and measurements in the high-frequency bands become necessary.
Pogo pins are generally used for electric connection of a test head and a probe card in a semiconductor test apparatus. Pogo pins are also called connector pins, probe pins, and spring pins and they can maintain the measurement accuracy when used for measuring DC signals or low-frequency signals.
However, when high-frequency signals in a HF band or RF band are measured, the measurement accuracy is difficult to maintain with the pogo pins due to a reflection loss or the like. Accordingly, when high-frequency signals in a HF band or RF band are measured, coaxial connectors for HF or RF signals have to be used in the connection portions of the test head and probe card.
Engagement of coaxial connectors is usually conducted by manually attaching coaxial cables one by one to coaxial connectors. However, the applicant has invented and patented a connector that enables automatic engagement even of coaxial connectors (Japanese Patent Applications Laid-open No. 10-106677). In the case where coaxial connectors capable of automatic engagement are provided at an interface for connecting a test head and a probe card and the interface is employed in a semiconductor test apparatus in which a dry gas can be introduced between the test head and probe card, the following problems are encountered.